diff --git a/src/Entity/Index.php b/src/Entity/Index.php
index 7be92cd..4597dbf 100644
--- a/src/Entity/Index.php
+++ b/src/Entity/Index.php
@@ -209,6 +209,12 @@ class Index extends ConfigEntityBase implements IndexInterface {
    */
   protected $cachedFields;
 
+  /**
+   * An array of field settings.
+   *
+   * @var array
+   *   An array containing field settings.
+   */
   protected $fields = array();
 
   /**
@@ -254,6 +260,12 @@ class Index extends ConfigEntityBase implements IndexInterface {
    */
   protected $processorInstances;
 
+  /**
+   * The array of processor settings.
+   *
+   * @var array
+   *   An array containing processor settings.
+   */
   protected $processors = array();
 
   /**
diff --git a/src/IndexInterface.php b/src/IndexInterface.php
index 03c2674..4beffb7 100644
--- a/src/IndexInterface.php
+++ b/src/IndexInterface.php
@@ -132,9 +132,6 @@ interface IndexInterface extends ConfigEntityInterface {
    */
   public function getDatasourceIds();
 
-  public function getFields();
-  public function setFields(array $fields);
-
   /**
    * Determines whether the given datasource ID is valid for this index.
    *
@@ -179,6 +176,24 @@ interface IndexInterface extends ConfigEntityInterface {
   public function getDatasources($only_enabled = TRUE);
 
   /**
+   * Retrieves this index's field settings
+   *
+   * @return array
+   *   An array of field settings
+   */
+  public function getFields();
+
+  /**
+   * Sets this index's field settings
+   *
+   * @param array $fields
+   *   An array of field settings.
+   *
+   * @return $this
+   */
+  public function setFields(array $fields);
+
+  /**
    * Determines whether the tracker is valid.
    *
    * @return bool
@@ -280,16 +295,17 @@ interface IndexInterface extends ConfigEntityInterface {
   public function getProcessorsByStage($stage, $only_enabled = TRUE);
 
   /**
-   * Sets processor settings.
+   * Sets this index's processor settings.
    *
    * @param array $processors
    *   An array of processors and it's settings.
+   *
    * @return $this
    */
   public function setProcessorSettings(array $processors);
 
   /**
-   * Gets processor settings.
+   * Retrieves this index's processor settings.
    *
    * @return array
    *   An array of processors and it's settings.